The production of natural gas or oil from a wellhead to the customer is a lengthy process that involves many separate production operations that transform the raw material from the ground to the refined product that the customer consumes. The entire operation requires many individual companies, each of which takes ownership of the stream in order to perform their particular operation. During this lengthy process, the material changes custody many times and is put through various preparation and refinement operations. From the wellhead to the customer user point, the conditions and composition of the material require differing processes. Material prepared for the collection lines that transfer it from the wellhead to a midstream refinery are heavily processed. The preparation at the well head most often involves both a dewatering operation and compression operation. Once a suitable specification is realized, the material is charged into the collection lines that transmit it to the midstream refinery. The midstream refinery is connected to a web network of underground piping that serves to supply the refinery from the many wellheads in the network. The midstream refinery receives the product and sends it to the slug catcher. The product then proceeds to a further dewatering system and then to the cryo unit, where it is processed to separate out natural gas liquids (NGLs), and is broken into individual components for further refinement. These components are further dried and processed with some of the stream prepared to specification for sale. Specification quality material will then be transferred by another underground network to a contracted buyer, with the remainder delivered via an underground network to a fractionating plant for further processing of specialty type gases and products. The liquids themselves are collected and transferred via a pipe line, train, or truck to contracted buyers. Specification quality methane from the midstream refinery is transferred via an underground pipe line to natural gas energy suppliers. These suppliers serve as the distribution network to the public consumer.
These operations involve diverse process equipment and piping systems and are subject to process upsets, maintenance, and raw material variables that are a part of any industry. In dealing with these realities, the gas industry has procedures and operations in place to mitigate loss of production and loss of raw material product. Some of these operations require the venting of product to the atmosphere. This has historically been accepted as an operational industry practice. The real loss of profit due to atmospheric venting is revenue not realized through sales of vented volumes and U.S. Environmental Protection Agency (EPA) emissions limitations and regulation costs.
Thus, there is a long felt need for a system that recovers trapped gas that would otherwise be vented to the atmosphere. There is also a long felt need for a metering system to measure the amount of trapped gas that is recovered.